Utilization of Swine Manure in a Polyculture of Asian and North American Fishes

Abstract

Chinese methods of fish culture were evaluated for potential use in animal waste management, pollution control, and the production of protein. Two ponds were stocked with grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molotrix), bighead carp (Aristichthys nobilis), carp (Cyprinus carpio), northern largemouth bass (Micropterus salmoides salmoides), channel catfish (Ictalurus punctatus), and the hybrid of bigmouth buffalo female (Ictiobus cyprinellus) and black buffalo male (I. niger). One pond (0.127 hectare) received the total wastes from five growing pigs (about 39 pigs/hectare of water area), the other pond (0.121 hectare) received the wastes from eight pigs (66 pigs/hectare). Two consecutive lots of pigs were fattened during the study. Over a fish-growing period of about 170 days (May to October 1975) the net increments in fish biomass were 2,971 kg/hectare in the 0.127-hectare pond and 3,834 kg/hectare in the 0.121-hectare pond. A beneficial influence by the fish on water quality was indicated by continuously adequate levels of dissolved oxygen, and final biochemical oxygen demands in the range of 8-12 mg/liter.